Of course statistics can be twisted to show almost anything you want.
There are two numbers that are fairly reliable, the number of listings and the number and value of transactions, both are UP year on year although the pace is as can be expected slowing if not in base numbers at leats in percentage terms.
I don't think eBay needs to spend any more money on marketing (it only increases their overhead, leading to fee increases). Thanks for giant corn flakes and "rare" grilled cheese sandwiches there are few people on the planet that don't already know what eBay is.
My sales are down a bit from last year, about the same as the year before and way down from 2002 when I was maintaining about 50% more listings than I am now.
If you have the widgets the people want at the right price and have enough listings the sales will be there. A much greater negative impact on my business has been the exchange rates which obviously are not the fault of eBay.
The OP referred to "dramatic" price increases, I don't have a store and don't use gallery, the only change is a slight one for BIN, not what I would call dramatic.
The big change is with stores and they have been underpriced compared to the auction format all along. It was inevitable that they would try to even this out at some point.
My mother (89) has NEVER used a computer, doesn't watch TV, only listens to CBC radio and doesn't read any magazines where eBay have advertised but even she knows about eBay (although she doesn't quite understand what it is).
List more = Sell more and if it doesn't then switch product lines or move on to another career.
Ben

"What else could I do? I had no trade so I became a peddler" - Lazarus Greenberg 1915
- answering Trolls is voluntary, my policy is not to participate.